Inserting an intravenous line (IV) requires knowing where a suitable vein or other blood vessel is located and how large a needle the vein will support. For non-Caucasian individuals, females, small children and neonates, the elderly, obese individuals, those who have acute medical problems, and others, veins may not be visible. Individuals who exhibit more than one of the above traits often have veins that can be very difficult to find and may require multiple attempts to insert an IV.
In these difficult cases, caregivers have traditionally resulted to palpating the area around a potential vein site rather than locating a vein visually. When dealing with sick individuals, or when working in an area where spread of contagious diseases is likely, such as a hospital, this may not be possible. Blood pressure may be too low, or a vein may be buried too deeply to find by touch. Regulations designed to halt the spread of MRZA or other contagion may require the caregiver to wear gloves, severely diminishing touch sensitivity and the chances of finding a suitable vein. Problems with inserting a needle into a vein can result in escalation procedures which require additional personnel to become involved or a central line to be inserted by surgery adding to infection risk and compromising patient safety. In all cases, critical time and resources are wasted, patient discomfort is increased, and patient care is compromised.
Many of the existing vein viewers on the market use near IR illumination, a technique originally popularized by Eastman Kodak and published in “Medical Infrared Photography” (N−1), Eastman Kodak Company, 1969. The near IR radiation is transmitted and scattered by the skin and absorbed by the hemoglobin in the veins. Therefore, in near IR light, the area above a vein appears darker due to the hemoglobin absorption than the area around it.
When preparing to insert an IV, the user generally goes through two distinct phases, surveying the area to find a suitable site, and inserting the needle into the vein at the site. Existing vein viewers suffer from some or all of the following drawbacks: they require more than one person or more than two hands to operate the device and insert a needle in the patient; obstruct a user's view of a needle insertion site; have poor contrast and need dimmed light; require external device support to free a hand for IV insertion; and don't provide magnification. Some vein viewers require the user to change focus between viewing an image of an insertion site and actual insertion site; they don't remain stationary during needle insertion; and add mass to the needle insertion motion negatively impacting the ability to properly insert a needle. Some related patents include: U.S. Pat. Nos. 4,817,622; 5,519,208; 6,230,046; 6,032,070; and 7,904,138. Thus, there is a need for an improved blood vessel or body tissue imaging device and method that overcomes the drawbacks of existing vein viewers.